This invention is directed toward a series of devices designed to scare away Great Blue Herons, raccoons, and other common koi pond predators through a combination of a motion detection system which triggers an auditory and/or movement response from a variety of replicas of common enemies of koi pond predators. The invention teaches the combination of the motion detector with the koi predator enemy replica, such that a koi pond user can economically and efficiently protect a koi pond without adversely impacting the visual appeal of a koi pond.
People have been keeping koi and other ornamental fishes as pets for centuries. One of the more popular methods of keeping koi is to place them in an outdoor pond. Ponds, ranging in size from several feet across to several acres, can be constructed anywhere the air temperature allows the fish to survive winter temperatures.
While koi ponds have proven to be one of the more attractive ways to keep koi, there are inherent problems with locating large numbers of colorful, and therefore easily seen, fish in an exposed, frequently shallow, outdoor pond. Predators such as raccoons and herons can empty a koi pond in less than an hour, consuming, in the case of valuable species, hundreds or thousands of dollars worth of fish in one feeding session.
Repelling these predators has become a major concern for koi pond owners. Among the methods used in past have been plastic animals, wire systems, and netting systems. The least expensive method is to put a plastic replica of a natural enemy of the herons and raccoons near the pond, with the hope that the plastic animal will deter the raccoon or heron from approaching the pond. Most popular among these are plastic great horned owls, available at many hardware and home improvement stores, which are placed around the pond, in a tree overlooking the pond, or on a roof above the pond. Also being used are plastic alligator heads, which float on the surface of the water, and floating pelicans, although it is questionable how many koi predators would be deterred by a pelican. Disadvantages of plastic replicas include the fact that because they don't move, particularly in response to a movement of the predator, the predator can become accustomed to the presence of the predator replica. Another disadvantage is that there are such a limited number of natural enemies of koi predators, there is a danger that the replica a koi pond owner buys will not be seen by the koi predator as a danger. For example, it is questionable whether a Great Blue Heron in California would recognize a plastic alligator as a natural enemy, since there are no naturally occurring alligators west of the Mississippi. A final disadvantage is that the plastic replicas are often not realistically painted so that a koi predator, given the time to examine the replica, could determine that the replica was indeed a fake animal. The time a koi predator has to examine the replica is key; if the predator is scared away before it can examine the replica, the replica can serve as an effective deterrent for generations of koi predators. If a koi predator has enough time to assess the enemy replica and determine it presents no threat, this fact can be passed on to its young and within several generations the enemy replica can become virtually useless as a deterrent.
Another approach to protecting a pond is to prevent or inhibit access to the pond by koi predators. One such approach is a wire system, involving a series of wires cross-linked above the pool, such as that found in US Patent application 20040119058 to Burdick (2004). The main disadvantage of wire systems are visual impairment and access limitations. Even though these inventions use thin wire, there still remains a series of wires across the pond, which detracts from the visual appeal of the colorful fish swimming beneath the wires. The wire systems can also inhibit the ability of a pool owner to access the pond to tend water plants, clean a filter, or even feed the fish. Additionally, many of the common plastic liner ponds allow a user to catch the fish and put them in a bucket, then drain the pond, remove it from its hole, and clean it before reinserting it, filling it with water, and putting the fish back in. A wire system would have to be taken down before such actions, thereby adding to the inconvenience factor in cleaning a pond. A final problem presented by wire systems is the chance that a koi predator, particular a heron, egret or other large bird, will become entangled in the wire and die or injure itself. Most koi owners wish no harm on the koi predators—which are just trying to eat—and would prefer to use a system which does not harm the predators. Additionally, a homeowner may run afoul of fish and wildlife laws if a protected animal dies or is injured in such a device.
Netting systems work on a principal similar to wire systems: a physical screen that keeps a koi predator from accessing the koi pond. Unlike the wire systems that are installed directly above and around the pond, netting systems are usually strung eight to twenty feet above the pond, and create a small “house” around the koi pond. Like the wire systems, netting systems are meant to be unobtrusive, and made from thin mesh netting that will withstand the rigors of an outdoor setting. Thin mesh will also cast as little shade as possible. At the same time, the shading provided by a netting system can inhibit the growth of pond plants, which usually do best in full sun, and should the screen be ripped during a windy day or rainstorm, the koi predators can gain easy access. Netting systems also pose the danger of entangling koi predators, which raise the same moral and legal problems as do wire systems.
Another approach used in the past is to have a motion detector trigger an “enemy replica” to move such that an animal will be scared away. The prior art discloses two inventions which combine motion detection with a response designed to frighten away animals. U.S. Pat. No. 4,450,063 to Peterson (1995) teaches a complex system of microwave, radar, or other signal generation and receiving arrangements which trigger responses, including noise, light, and motion from objects, including predator bird replicas, upon a bird's triggering the motion detection systems. This invention is directed toward a method of keeping birds from landing on a polluted pond or wetlands area, and is relatively complex and costly. It is also fairly fixed in place and although there is some flexibility in the computer-programmed responses, the system is not readily or economically adaptable to the home koi pond environment, where different situations and seasons may require the moving or rearranging of the predator enemy replicas.
The Scarecrow by Bird-X, a company specializing in bird repellant devices, is basically a sprinkler head hooked up to a pressurized water hose with a motion detector that, when detecting motion, opens a valve which releases a three-second burst of water intended to scare away koi predators. The Scarecrow, because it is hooked up to a pressurized water source, is subject to the leaks, burst washer gaskets, and exploding hoses that are inherent to a constantly pressurized system. Since there is a wide range of garden hoses, varying in quality from reinforced hoses that can withstand constant pressurization to cheaper models which balloon out, split, leak, and otherwise malfunction under any kind of extended water pressure, inventions such as The Scarecrow may result in substantial damage (and high water bills) due to malfunctioning of devices, such as hoses, upon which they rely. The Scarecrow is also designed such that the water jets out directly above the motion detector, thereby subjecting the internal electrical parts to potentially severe conditions should water seep inside of the motion detector. In addition, the Scarecrow could cause a burst of water to touch the koi predator, which in the case of a Great Blue Heron and other waterfowl, could be viewed by the US Department of Fish and Game or the state or local law enforcement divisions as a violation of the law. Finally, the Scarecrow also provides only one response—a three-second burst of water—which may allow some koi predators to become accustomed to it, thereby decreasing its effectiveness.
Thus there has existed a long-felt need for a self-contained, inexpensive invention which can scare away koi predators, not visually impair the enjoyment of the koi pond, or physically impair a user's ability to access the koi pond, and rely upon neither external hoses or other common garden items that are subject to wear and tear, nor complex and expensive computers and radar/microwave systems.
The current invention provides just such a solution by having a koi predator enemy replica which responds to the motions of the koi predator, thereby more accurately mimicking a real animal than those in the prior art. The invention also does not shade the pond, as does a netting system, nor does it result in visual impairment and physical limitations as does a wire system, and is fully self-contained, thereby making its arrangement.